Tapping machine



May 4, 1943. L. a SCHAUER TAPPING MACHINE Original Filed Dec. 13, 1935 3 Sheets-Sheet 2 NM 4 WM QM l I mlm b INVENTOR ATTORNEY 1943- LE. SCHAUER 2,318,336

' 'rArrme mourns Origifial Filed Dec. 13, 1935 3 Sheets-Sheet 3 INVENTOR FIG. 8 3? i--ARM UNCLAMPED 9? 2 ATTORNEY Patented May 4, 1943 TAP-PING MACHINE Lawrence Lee Schauer, Wyoming, Ohio, assignor to The Cincinnati Bickiord Tool Company, Cincinnati, Ohio, a corporation 01' Ohio Original application December'13, 1935, Serial No. 54,206. Divided and this application December 30, 1936, Serial No. 118,245

29 Claims. (01. -136) This invention relates to improvements in tapping machines in general and more particularly to an improved method and means for expeditiously locating and controlling the movements of the tap spindle.

The invention is particularly adapted to machines of the general character disclosed in my prior application Ser. No. 54,206, filed Dec. 13, 1935, which is directed to drilling and drilling functions of machines of the type disclosed whereas the present application, which is a division of said prior application, is directed to'tapping and tapping functions of such machines.

A primary aim of the invention is to render available a tapping machine in which the operator is given a finger-tip control over the starting, stopping and directions of translatory and rotary motions of the tap spindle through a control lever located adjacent the normal working station.

A further aim of the invention is to coordinate the controls for the forward, reverse and axial motions of the tap spindle into a single lever arranged and located with respect to other control levers as to render it unnecessary for the operator to remove his hands from the controls during the performance of a tapping operation or a succession of such operations.

Still a further objective of the invention is to eliminate the heretofore essential mechanical reversing means and to accomplish the reversing functions in a more rapid and certain manner involving mechanisms relatively inexpensive from the standpoint of both original cost and maintenance.

Another aim of the invention is to .render available a direct drive machine having all of the operating characteristics of a drilling machine in addition to the tapping characteristics whereby the machine may be used as an ordinary drilling machine or as a tapping machine. Byway of further refinement, the invention further aims to render available a combination drilling and tapping machine having a plurality of sets of controls cooperatively arranged so that conflicting motions are definitely precluded.

The invention further aims to provide a tapping machine having radial drill characteristics and to inter-relate the controls for the. arm elevating and clamping functions with the controls for the spindle feed and rotary motions in a manner eliminating all need for positive mechanical interlocks. In the past, mechanical interlocks were designed as to positively prevent an operator from adjusting the position of a control lever unless some other lever was in a predetermined position. With such arrangements an operator frequently would attempt to shift a lever only to find, after persistent effort,

' that it was locked and could not be moved. Consequently, .by reason of the complicated andsomewhat delicate nature of mechanical interlocks, it was not long before the mechanism was forced out of adjustment and unfit for use. Furthermore, the designing of mechanical interlocks followed the designing of the primary mechanisms and this rendered the safety mechanisms in the nature of auxiliaries or attachments, which could, comparatively easily, be removed or ren-- that end the levers and the mechanisms actuated I thereby have been so related that the first lever actuated by the operator, efiects operation of a master control which retains its control over the moving machine elements, to the exclusion of all other manually operable levers, until the lever first operated is again positioned so as to render movement of the other lever or levers effective.

The'present invention is particularly adapted to tapping machines in which the tap spindle is mounted for lateral movement along an adjustable but normal stationary arm member. In a tapping machine of this character the arm or support is adjusted by power to the proper height and clamped in position, the angular position of the arm andthe position of the tap spindle on the arm is then determined by the operator at his station at the front of the tapping head. With the present invention the control for raising or lowering the arm and for clamping the arm, is located at the column of the machine,

whereas, the controls for governing the starting,

stopping and direction of motion of the tap, as well as the tap feed, are located on the tapping head and adjustable therewith.

In carrying out the objectives of the invention, a reversible electric motor is employed tov propel the spindle in reverse directions-and to raise and lower the arm. A master control for the motor is provided which in turnis rendered rotary and axial motions of the tap spindle.

plurality of controls on the drill head, each control serving to govern the starting and stopping. and direction of movement of the tool spindle, so placed and related with respect to other cooperative controls as to be conveniently within reach of the operator with particular reference to the character of the operation performed. For ex ample, for ordinary drilling, a power feed is used which is normally controlled by the operator's right hand, the spindle control for that operation is arranged for convenient operation with the operator's left hand. For tapping operations it'is customary in the large majority of cases to have the tap feed itself into the work and to control forward and reverse movements of the spindle manually. With the present invention the spindle control for such operations is conveniently arranged and located so as to be operable with the operator's right hand, thus. leaving the operators left hand free to eifect relative movement between the work and spindle for purposes of properly locating the work with respect to the tool.

The'means for feeding the spindle toward or from the workpiece is also arranged to be controlled with the operators right hand and interrelated with the prime mover so that one is assured that before the forward or reverse feed of the indle is brought about, the prime mover and spindle are previously put in motion in the proper direction. Thus an operator may, without removing either hand from the several control elements effect a plurality of separate tapping operations in rapid succession.

Preferably an induction type motor capable of yielding approximately twenty reversals a minute is selected for this use. The motor is also arranged to be connected at will to the arm elevating mechanism whereby the arm may be elevated or lowered depending upon the direction of movement of the motor.

The controls for the motor are inter-related with the operation of the arm clamp and arm elevating mechanism and so arranged that when the arm is clamped? the arm elevating mechanism is rendered ineffective and the controls on the tool head rendered effective to control the On the other hand when the arm is unclamped and the elevating control set for elevating or lowering, actuation of the head mounted controls have no eil'ect upon the action of the prime mover.

In carrying out that objective without the use of positive mechanical interlocks, the head mounted control means of the present invention includes two sets of control switches connected in parallel with a set of arm elevating switches,

.each of the headsets however, being preferably in series with a cut-out switch operated by the arm elevating control lever, which affords the additional safety above mentioned. One set of the head switches. is adapted to be actuated by a lever at the left side of the head, and the other set arranged to be actuated by a handle at the right side of the drill head, and the latter handle Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of which:

Figure 1 is an assembly view of a machine incorporating the present invention.

Fig. 2 is a vertical sectional view through the tool head illustrating portions of the spindle rotating and power feed gearing.

Figs. 3 and 4 are sectional views through the tool head more clearly showing the manual feed means and the locations and relation of the reversing controls for the tap spindle.

Fig. 5 is a detail view of manual means for adlusting the head on the arm in locating the tap spindle where desired.

Fig. 6 is a sectional view through a portion of the arm and column illustrating the arm clamping and elevating means and controls therefor.

Fig. 7 is a fragmentary view of the rear of the machine.

Fig. 8 is a diagrammatic view of the arm clamping and elevating control lever and its connections.

Fig. 9 is a circuit diagram of trol.

Fig. 10 is a portion of the control'circuit somewhat modified.

Referring more particularly to Fig. l of the drawings, the machine illustrated comprises a base member I! which supports a column l6 and a rotatable sleeve l1. A translatable arm I! is the electrical conmounted on the sleeve and supports a laterally translatable tool head IS. A rotatable and axially translatable tap spindle 20 is journaled in the head l9 and driven selectively in reverse directions by a reversible direct connected motor 2|. The motor 2| is preferably of the type that may be reversed as frequently as twenty times per minute without injury, for reasons that willappear more fully hereinafter.

A direct drive to the tool spindle 20 is efl'ected through the arm shaft 22 that is fully enclosed within the arm l8, as illustrated more clearly in Fig.2, and power enters the head at the rear. For this purpose the head member I! is provided with a depending bracket 23 within which is journaled a pair of beveled gears 24 which transmit the motions of the shaft 22 to a vertical shaft 25 leading into the head proper. Change gears indicated generally a 26 transmit the motions from shaft 25 to the translatable spindle 28, splined to the ultimate drive element of the drive t ain .26.

asiaaao Power is taken off the spindle'shaft to a set of feed change gears 28 which has its final elementin the form of a Vertically arranged feed shaft 29, the lower end of which is providedgvith a worm 30 that meshes with a worm wheeyijj normally loose upon a feed pinion shaft 32. A clutch element 33 is interposed between the worm wheel and the feed pinion shaft and is adapted to be actuated manually to connect the worm wheel positively with the shaft 32.

58. The opposite end of the lever 53 engages] theend of the cam shaft 40 and, when the lever is rocked by the action of the push pin 51, the

translation being determined by the setting of change gears 26 within the head proper.

The power feed clutch 33 comprises essentially to the pinion shaft 32. The head 36 has two spring pressed levers 31 pivoted thereto each of which is provided with a series of serrations offset from the plane of the lever adapted to engage the teeth of a serrated ring 38 carried by the worm wheel 3|. The ends of the clutch levers engage radial pins 33, only one of which is shown in Fig. 4, which in turn engage a central cam shaft 40 slidably mounted in a central bore in the pinion shaft. with a low portion 4| and a high portion 42, and when the shaft 40 is moved so that the pins 39 The cam shaft 40 is provided ride on the high portion of the cam, the clutch teeth are engaged, and when the cam shaft 40 is moved outwardly, the spring pressed levers 31 are free to disengage themselves from the worm wheel and the power feed ceases. A pair of control levers 43, which have a tooth connection 44 with the cam shaft, pivoted to the head bracket to the position shown in Fig. 4 and the power feed is thrown out automatically at that point.

The power feed throw-out just explained applies to the means for throwing out the power feed at predetermined points intermediate the normal extremes of spindle movement, and to safeguard the machine elements against an attempt inadvertently to propel the spindle axially beyond certain limits in either direction, a safety feed throw-out and spindle stop mechanism'is provided. Referring more particularly to Figs.

'3 and 4, this safety mechanism includes a gear 48 keyed to the pinion shaft which meshes with a gear" on a transverse shaft. The gear 49 carries at its outer end another gear 50 which meshes constantly with a gear 5! of a compound gear unit 52. The other gear 53 of the unit meshes with a gear 54 rotatably mounted upon the hub of the bevel gear 49. The gear 54' is provided with a double face cam 55 which maintains an invariable relation with the spindle so that, as the spindle approaches either end of its normally available movement, the cam 55 engages a stop pin 56 whereby the translatory cam shaft 40 is automatically shifted to its clutch disengaged position. A slight further movement of the cam 55, from whatever cause, brings the cam into the engagement with the stop 56 and further movement is positively precluded.

In the position of the parts illustrated in Fig. 4, the hand levers 43 may be aotuated'manually in an angular direction to propel the spindle up or down as desired. This movement, however, is relatively rapid and is used primarily for drilling purposes. A relatively slow but very powerful manual feed movement may be imparted to the spindle by means of the lever 59'mount'ed at the right side of the tool head. The lever 5.9 when not in use is latched'out of action by the latchmechanism 60. A toothed wheel 62 mounted on the shaft 63 cooperates with the latch mechanism when it is desired to use the lever 59 for feeding the spindle. When the latch 6|! is released the plunger 5i, forming part thereof, engages the teeth of the wheel 52 and the latter is propelled as the lever is moved about its hub. This movement also propels the shaft 63 to which is secured the reduction gear unit 52 and, through-gears 5 I,

50, 49 and 48, may be used to drive the feed pinion shaft 32. When the spindle is being fed through the mechanisms last explained, the safety stop mechanism operates a above set forth to protect the parts frominjury irrespective of the direction of spindle translation.

The auxiliary hand-grasp 64 which provides part of the tapping features of the present invention, later 'to be explained in detail, is also secured to an extension of the'shaft 63 through the medium of a pin and slot mechanism 65 and 56. The slot 66 is in the form of a helix which extends part way around the shaft 63 and is engaged by a roller 65 carried by the hand-grasp 64. Thus, when the hand-grasp is 'tumed in either direction from the position illustrated in Figs. 3 and 4, it is moved axiallyof the shaft 63 a-slight distance and when the roller 65 reaches the end of the groove 56 a positive connection is made with the shaft 63 and further rotary movement of the hand-grasp propels the spindle.-

Spring detent means 14 is provided for the purpose of imposing sumcient friction to hold the hand grasp at either end of the cam groove or in an intermediate position. Should it be desired, however, to eliminate the float of the hand grasp a screw 15, which forms part of the friction imarm elevating and clamping mechanism which will now briefly be described.

Referring now to Figs. 6, 7 and 8, it will be ob- However, if the power served that the arm shaft 221s connected directly worm 18 meshes with a worm wheel 13 which in turn carries a gear 14 in mesh with a gear 18 on the rotatable arm elevating nut 18. The nut 18 engages the elevating screw 11: and by means of which the arm may be raised or lowered by power, provided the clutch 1| is engaged and the motor 2| in operation.

When the arm has been shifted to its proper height it is clamped in position by a combined column clamp and elevating control lever 18. The lever 18 operates in a modified H-slot (see Fig. 8) and has its fulcrum point 19 in an annular groove in a fixed casing. When the lever 18 is in the position illustrated in Fig. 6, clutch teeth 88 thereon engage complemental teeth provided at the outer end of a shouldered sleeve 8|. The inner end of the sleeve 8| operatively engages an adjustable clamp nut 82 and when the lever is moved counterclockwise to the position shown in Fig. 8, the arm is clamped firmly to the column l1 by the action of the sleeve 8| and nut 82 drawing the split portions of the arm girdle together.

The same lever 18 also is used to operate the elevating clutch 1|. The mechanism for this purpose includes a translatable and axially movable shaft 83 to which the lever 18 has a pivoted connection. A lever 84 and a link 85 transmit the motion of the shaft 83 to a clutch shifting lever 86. The lever 84 is normally free on the shaft 88 but may be clutched thereto by means of the gear 81 on the shaft 83 and a complemental clutch element 88 formed on the hub of the lever 84. In the position of the parts shown in Fig. 6, the shaft 83 and gear 81 have been moved axially inwardly whereby the gear 81 is disengaged from the internal teeth88. However, when the lever 18 is moved outwardly to the other leg of the modified H-slot, the gear 81 moves into engagement with the clutch teeth 88. Angular movement of the control lever 18 in the outer leg of the H-slot (clamp clutch teeth 88 disengaged) rotates the shaft 83 and effects oscillation of the lever 84 connected with the elevating clutch shifting lever 88. As will be seen from Fig. 7,.the connections between the parts 84, 85 and 86 are so relatedthat angular movement of the control lever 18 in either direction from the position illustrated will effect an engagement of the power elevating clutch 1|.

The shaft 83 is also provided with a safety throw-out lever 88 which moves into the path of the notched bar 98 carried by the radial arm when the control lever 18 is positioned for elevating or lowering the arm. The bar 98 projects through the top and bottom sides of the arm and is adapted to engage an abutment at the top of the sleeve and at the bottom of the sleeve so as to limit the normal extremes of movement of the arm. Should the operator inadvertently hold the lever 18 in either the arm elevating or lowering position, the arm will move until the safety bar 75' tion of arm movement being indicated in general 88 contacts with the dog on the column sleeve. Further movement of the arm will effect a shifting of the safety bar 88, and as this bar now will engage the lateral lever 89 fin the control shaft, the control shaft is automatically oscillated to a position such that the arm elevating clutch 1| is positively withdrawn.

From the foregoing explained devices, it will be evident that it is impossible to shift the arm when the arm is clamped, or to clamp the arm while the arm is in motion for the reason that the clutch teeth 88 can never engage the teeth on the clamp sleeve 8| at. the same time that the teeth 81 at the opposite end of the shaft engage the coacting teeth 88 of the clutch shifting mechanism, and for the further reason that the modified H- slot positively prevents endwise movement of the control shaft 83 unless the lever 18 is brought into coincidence with the transverse channel of the H-slot. The lever 18 can be in the latter position only when the arm is unclamped.

In addition to the functions previously explained, the control lever 18 also is one of the controlling instrumentalities for the reversing motor 2|. So that it will be unnecessary for the operator to actuate a separate lever to move the arm up or down after engaging the power clutch with the lever 18, the elevating clutch shifting lever 84 carries a switch actuating cam 93 which operates on two normally open motor control switches e and d. In the position shown in Fig. '1, the switches e and d and the cam 93 are illustrated in their neutral'positions which correspond with the transverse channel of the'H-slot.

H-slot, the gear 81 is disengaged from the clutch 88 and cam 93, angular movement of the lever therefore has no effect on the position of switch cam 93. However, when the lever 18 is moved to the outer slot, clutch elements 81 and 88 are brought into engagement and angular movement of the lever rotates the cam 93 thereby to cause the motor 2| to operate selectively in a forward or a reverse direction and simultaneously engages the power elevating clutch 1|. The arm accordingly may be moved up or down to the extent desired by actuating only the lever 18, the direcby the direction the operator actuates the lever 18.

The preferred form of electrical control for governing arm and spindle movements is rep-' resented diagrammatically in Fig. 9 of the drawings. In this figure, the power lines L U and L which preferably enter the machine at the base, connect with the master motor reversing and control switch RS. The master switch is electrically operated and includes a forward solenoid F and a reverse solenoid R, each of which when energized moves the armature of the switch R8 to a position such that the motor will start and run in a forward or a reverse direction depending upon which solenoid is first energized. It is clear that if, for example, the solenoid R is energized the armature of the switch will be If d the lever 18 is operating inthe inner leg of the Hence, it is impossible for direction with one control lever and to reverse" the operation of the motor by another lever. The operator must restore the lever which first energ'ized one of the solenoids to a definite position and de-energize the solenoid before the other In the example given, the master control switch- R8 is in turn controlled by three sets of forward and reverse switches, A, B and C. The set A includes the switches e and d, previously mentioned, which are adapted to be actuated by the column clamp and elevating control lever 19; the set B which include switches r and connected in parallel with the set A, are located in the tool head l9 and controlled from the-lever 94; and the tapping set C which includes the switches j and 1'' connected in series with certain contacts of the set B are also located in the shiftable tool head and controlled from a manually operated member 64.

With the circuit described, the machine may be operated as follows: Movement of the elevating control lever 18 up, in the outer channel of the H-slot, engages the elevating clutch H, closes the switch e and completes the circuit through lines 13, 3, 4, reverse solenoid R,line 5,

to power line IF. The reverse solenoid R is thereby energized and moves the master switch RS to a position wherein the motor starts operating in a reverse direction and the radial arm proceeds to elevate. Movement of the elevating control lever 18 down past neutral to its other extreme position, opens the switch e disengages and again engages the elevating clutch I I, and closes the switch d. The reverse solenoid R is thereby de-energized and the forward solenoid F energized, and the master control switch RS thrown to the position wherein the motor runs in the forward direction. The arm is thus caused to descend. To stop the arm at any point the operator shifts the lever 18 to neutral at which point both switches e and d are opened and the solenoids F and R de-energized, the operator may then clamp the arm to the sleeve by shifting the control lever 18 to the inner channel and upward.

At the front of the tool head the operator by actuating the control lever 94, may similarly start, stop, and reverse movements of the tool spindle through the parallel set of switches B. The control lever 94 is used primarily for drilling operations and is connected to the set of switches B, shown more clearly in Fig. 3. In this figure, the lever 94 operates a bell crank lever 95 mounted within the tool head which in turn is connected to a switch operating shaft 96. Detent means 91 are provided to hold the switch in either effective position or in neutral.

When the lever 94 is moved down, switch f is closed which completes the circuit to the forward solenoid F and the tool spindle runs in a forward direction. When the lever 94 is moved up the switch 1' isclosed and the tool spindle runs in a reverse direction and when the lever 94 is in its intermediate or neutral position, circuit is establishedthrough lines 3, I, 9 and 9 to the V tapping control switch C; this last mentioned switch is operated from the spindle translating hand-grasp 64.

For tapping operations the operator controls the rotary motions of the tapthrough the 'handgrasp 64 as follows: A slight turn of the handgrasp 64 ina counter-clockwise direction, as viewedfrom the right side of the head, shifts the hand-grasp bodily to the left which movement through the shifting fork 99 effects the closing of the forward switch I of the set C. With the switches of the set E in the position shown in Fig. 9, the closing of the switch I starts the tap spindle rotating in a forward direction. Continued movement of the hand-grasp '64 in the same direction propels the tap spindle down-.

wardly into the workand when the tap takes hold in the work, it feeds itself. When the proper depth of thread has been cut, a slight movement of the hand-grasp 64 in the opposite directionopens switch I and closes the reverse switch 1" and the tap spindle is instantly reversed and the tap automatically feeds out of the tapped hole. When the tap has backed entirely out of the hole, the operator may translate the spindle axially upwardly a further distance by rotating the hand-grasp 64 and then stop all rotary and axial movement of the tap spindle by giving the hand-grasp a slight countermovement. In this construction, it will be observed, the parts are so arranged and related that the direction the hand-grasp 64 is rotated indicates the direction of rotation of the spindle, and simultaneously in the direction of axial feed, and to stop the motion, it is merely necessary to hold back on the hand-grasp 64 until the roller and slot connec tion 65 cams the hand-grasp to its neutral position. If the hand-grasp is actuated beyond its neutral position, the rotary motion of the tap :pindle immediately starts in the reverse direcion.

The functions performed by the hand-grasp 64 are in addition to any function that may be performed by the conventional quick traverse levers 43. These levers 43 are used in setting up the machine and'in testing to See'if there is sufficient axial motion remaining available for a particular operation. As hereinabove explained the levers 43 also actuate the power feed clutch 33, but have no control over the rotary motions of the spindle.

From the foregoing, it will be perceived that an operator may, by this invention, exercise complete control over all motions of the tap spindle through the single element 64, and as this element is located at the right side of the tool head, it will normally be actuated by an operator right hand. This enables the operator to use his left hand in actuating the head traversing mechanism 99 to adjust the head along the arm and relocate the tap for the succeeding tapping opera on.

The head traversing mechanism 99 and tapping control element 64 have been further designed with a view toward utilizing these elements as a means for swinging the arm and tool head angularly about the post IS in locating the tap laterally. Normally, for tapping operations,

the sleeve I1 is left unclainped from the column I6 and the head l9 unclamped from the arm in order that the tap spindle may float itself into the hole to be tapped without unduly straining or breaking the tap.

axial float of the tap relative to the spindle It will ordinarily be provided. However, it will be evident from the relation of the parts illustrated in Figs. 3, 4 and 9, that the starting or reversing of the rotary motions of the tap spindle will occur substantially simultaneously, if not slightly in advance of, the axial motions manually imparted to the tap spindle through the same instrumentality. And inasmuch as the rotary motions of the tap itself determine its rate of advance inor out of the tapped. hole, there is no danger of stripping threads or breaking the tap on the starting, stopping, or reversing of the motions at any point in the cycle of operations.

A further feature of the invention resides in the safety provided between the elevating control andthe spindle controls on the toolhead. Assuming that the switch B is in the neutral position shown in Fig. 9, or out of the circuit entirely, the tapping switch 0 is in parallel with the arm elevating switch A. This gives rise to a condition wherein it is possible for an operator to'start the spindle running in a forward direction through the hand-grasp M and then attempt to elevate the arm by shifting the lever 18 up. This movement of the lever 18 will close the ticularly when the power feed-is used, a slight, control in which the'set of switches C are connected in series with the forward switch 1' of the drilling set B. In this arrangement the control elevating switch e and energize the solenoid, but I inasmuch as solenoid F has previously been energized by the closing -of the tapping switch'j,

the subsequent energization of the solenoid R has no eifect .upon the action of the motor. In consequence, movement of the elevating control lever 18 up would engage the elevating clutch II and the arm would at once descend, contrary to the operators intentions.

To guard against such occurrences, a supplemental switch D is inserted in the .control circuit between the switch A and the switches B or C. The switch D is normally closed and ar-. ranged to be moved to its open position whenever the power elevated clutch H is actuated to its effective position. To that end,'the switch D is mounted preferably adjacent the clutch actuating lever 84 and is adapted to be actuated by the latter through the medium of a push pin III. A recess Jill is formed in the clutch lever 84 in a position which coincides with the pin I 00 when the power elevating clutch H is disengaged. In this position of the lever M, the control lever 18 is positioned somewhere along the transverse channel of the H-slot or in the inner channel thereof. If'the lever is in the horizontal channel and then moved to engage the power clutch II to effect movement of the arm up or down, it will be seen that the initial part of the movement to engagethe power clutch cams the pin Ill out of the recess III and opens the switch D. On the other hand if the lever 18 is in the inner channel of the H-slot, movement thereof has no effect upon the switches of the set A by reason of the action of the gear and clutch mechanism ll, 88, previously explained.

When the power elevating clutch H is engaged, the switch D is open, as above stated, and the circuit to the control switches of sets 13 and C is rendered incomplete. Accordingly, if an operator leaves the tapping control element 64 in an effective position, subsequent operation of the column clamping and elevating control lever 18 automatically renders the control circuits, initially completed by the tapping control element i4, ineffective and the operator is free of the danger of accidentally lowering the arm.

Fig. 10 illustrates a modified form of tapping lever 94 for drilling must be inits forward position before any control over the rotary motions of tap spindle may be exercised through the element I4, and the latter may be actuated to propel the spindle in either direction without startingthe power. a

While the foregoing explained circuits have been described with reference to the conventional right hand threading operations, it'will be un- I derstood that the machine is equall adaptable to left hand threading operations.

In the several circuits and controlling instrumentalities above described, it will be evident that any of the levers 18, 94, or e'len ent 64 may be actuated at any time to any of their normally eflective positions without restraint. Movement of a lever,'however, does not in itself effect its normal or intended function unless or until an interrelated control lever is in apredetermined position. This insures a definite sequence of operation of the several movable elements and,

spindle, effects the reversals thereof with the speed essential for this character of work. At the same'time, the operator may exercise complete control over all motions of the tap with the expenditure of a minimum amount of physical efiort. As-a result the user may quickly and emciently perform a number of separate tapping operations in rapid succession in a materially shorter length of time than has been possible .heretofore with manually operated mechanical controls and reversing mechanisms.

Without .further analysis, the foregoing will so fully reveal the gist of this invention that as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent ofthe United States:

1. In a tapping machine the combination of a support; an arm mounted for translation on said support; a tap spindle carried by the arm; a reversible electric motor; means for translating said arm onsaid support; continuously operative power transmitting connections between said motor and said spindle; connections between said motor and said arm translating means 'electively operable to effect translation of the arm on said support; control means for said motor including a first set of forward and reverse control switches adapted when selectively actuated to effect forward or reverse rotation of said spindle, a second set of forward and reverse Likewise the heretofore conven control switches adapted when selectively ac-' arm on said column selectively in reverse directions; continuously operative power transmitting connections between said motor and said tap spindle; interruptable power transmitting connections including an elevating clutch between said motor and said arm translating means; contioned manual means operative to eiiectieeding movements of said tap spindle; control means for said prime mover; and operative connections between said auxiliary feed means and said control means operative to eil'ect movement of said prime mover when said auxiliary feed means is actuated and inoperative'to eflect movement of said prime mover when said first mentioned trol means for said motor including a master reversing switch adapted when selectively actuated to effect forward or reverse rotation of said tap spindle or to eifect translation of said arm in either direction on-said support; a plurality of manually operable control means for a tap spindle joumaled in said head; a reversible electric motor; continuously operative power connections between said motor and said spindle for rotating said spindle in accordance with the direction of movement of the motor; control means for said motor including a lever having a forward and a reverse and a neutral position adapted when selectively actuated to one of its effective positions to effect forward or reverse rotation of said tap spindle; an elementhaving a forward and a reverse and a neutral position adapted when selectively actuated to one of its effective positions to likewise effect forward or reverse rotation of said tap spindle; and means operative to subdominate and render the actuation of said element ineffective to control spindle movement when said lever is actuated to one of its effective positions.

4. A tapping machine combining a tool head; a

rotatable and axially translatable spindle journaled therein; power means directly connected with said spindle for rotating same; control means for said power means; manually operable means for feeding said spindle axially comprising a feed pinion shaft operatively connected with the spindle, a second shaft connected to the said pinion shaft, a manually operable handgrasp mounted on said second shaft for rotating same thereby to propel said spindle axially, said hand-grasp having a lost motion connection with said second shaft and capable of movement a limited amount relative to the said shaft; and connections between said hand-grasp and id control means operative upon the initial mo ement of said hand-grasp to effect a starting of said power means substantially coincident with the starting of the translatory movement of said spindle effected through said hand-grasp.

5. A tapping machine combining a prime mov-- er movable selectively in forward and reverse translating means is actuated.

6. A machine tool combining a reversible motor; a tool spindle connected therewith and adapted to be rotated thereby; manual means for translating said spindle axially including a feed pinion shaft and a hand lever thereon for actuating said shaft; auxiliary manual means for translating said spindle comprising a shaft member geared to said pinion shaft, a, handgrasp element mounted upon said shaft member and movable angularly and axially relative thereto; means for limiting the angular movement of said hand-grasp relative to the shaft whereby angular movement of the hand-grasp beyond said limit effects rotation of said shaft member and translation of said spindle; and means actuated by the axial movement of the hand-grasp on said shaft for controlling the starting and stopping of said motor thereby manually to control the rotary movement of said spindle.

7. A tapping machine combining a prime mover movable in a forward or reverse direction; a tool spindle adapted to be rotated thereby; manually operable means for moving said spindle axially selectively in a forward or reverse direction at a relatively rapid rate; auxiliary manual means for feeding saidtool spindle axially at a relatively slow rate; and control means for said prime mover coordinated with said auxiliary manual means operative to effect movement of said prime mover in a reverse direction when said auxiliary manual means is actuated to move said spindle axially in a reverse direction.

8. A tapping machine combining a tool head;

a rotatable and axially movable spindle journaled in said head; a reversible prime mover and continuously operative connections therefrom to said spindle for rotating same selectively in opposite directions; a first manual means for feeding said spindle axially; and a single manually operable element located at the right side of said head for controlling the rotary movement and the direction of rotary movement of said spindle and for feeding said spindle; and means including a lost motion connection between said element and. said spindle operative to effect rotation of the spindle prior to any movement thereof axially by said second mentioned manual means.

9. A tapping machine combining an arm; a tool head mounted for translation on the arm;

a manually operable hand wheel located at the left side of said head for traversing said head along the arm selectively in either direction; a rotatable and axially movable spindle journaled in said head; a reversible prime mover and connections therefrom to said spindle for rotating same selectively in opposite directions; control means for the motor; manual means for translating said spindle axially; a single manually operable element located at the right side of said head for controlling selectively the movement and direction oi. movement of said prime mover and for feeding said spindle; and operative connections between said single element and said" control'means tor the prime mover and between said-element and said spindle for eiiecting rotary motion or the spindle in advance, in point of time, of any feeding movement imparted thereto by said element. v I

A machine tool combining an arm; a tool head mounted for translation on the arm; a manually operable hand wheel located at the asiasao left side of .said head for traversing said head laterally along the arm selectively in either direction; a rotatable and axially movable tapping splndle journaled in said head; a reversible prime mover and connections therefrom to said spindle for rotating same selectively in opposite directions; manual means for moving said spindle axially; direction control means for the prime mover; and a supplemental manually operable element located at the right side of said head for controlling the rotary movement and direction of rotary movement of said prime mover and for feeding said spindle whereby the' operator may locate said spindle laterally on the arm with one handand control its direction of to a position ineilective to control the action of said reversing meana; v

- 14. Atapping machine combining a tool head; a spindle rotatably and translatably mounted in the head; a' reversible electric motor; constantly operative driving connections between said'motor and said spindle; means for translating saidspindle; control means coordinated with said ently operable elements mounted upon the tool head; and means automatically operative to render the actuation of one of said elements ineffective to control, spindle movement when the operation of said reversible motor is under the control of the other of said levers.

16. A tapping machine" combining a tool head; a rotatable and axially movable spindle lournaled in the tool head; power means for rotating said rotation and direction axial movement with his other hand and perform a succession of tapping operations without removing either hand from said locating and controlling instrumentalities.

11. The combination set forth in claim 10 in which said supplemental manually operable element comprises a rotatable and axially shiftable hand-grasp, and operative connections between said hand-grasp and said spindle and between said hand-grasp and said direction co'ntrol means, on movement oi said hand-grasp controlling direction of rotation of the spindle and the other movementoi said hand-grasp controlling direction of axial movement of said spindle.

12. A tapping machine combining .a tool head; a rotatable and axially movable spindle journaled in the tool head; power means for rotating said spindle; reversing means for said power means; a plurality or manually operable controls for said reversing means, one of said controls being mounted on the right side of said tool head and another of said controls being mounted upon the left side of said head, each of said controls having a forward" a "neutral" and a "reverse position and each control being capable of movement from its neutral position to either of its efiective posi-' tions selectively simultaneously or consecutively;

and means coordinating the effective action of said controls so that the movement of one of said' controls to one of its effective positions dominates the effective action of the control moved subsequently thereto until the said first moved control has been moved to a predetermined position whereupon the movement of said subsequently actuated control becomes effective to control the rotary movements of said spindle.

13. A. tapping machine combining a prime mover; a spindle adapted to be driven therefrom; reversing means for the spindle; manually operable means for actuating said reversing and an auxiliary control element, and means automatically subordinating the eiiective action of said last mentioned control element to the action of said dominating control element until said dominating control element has been actuated ati spindle reversing means for sald'power means; a plurality of manually operable controls for said reversing means, each of said controls having a .forward-a neutral and a reverse position and each of said controls being capable of being moved from its neutral position to either of its efiective positions selectively simultaneouslyor consecutively; and means coordinating the effective action or said controls so that the move ment of one of said controls to its neutral position dominates the eil'ective action of the control moved subsequently thereto until the said first moved control has been moved to one of its ef fective positions whereupon said subsequently moved control automatically becomes efiective to control the movement and direction of movement of said spindle.

1'7. A tapping mechanism combining a translatable and rotatable tap-holding spindle; a ro-. tatable element mounted to be slightly shiftable longitudinally; reversible means controlled by said element for imparting power-rotations to said spindleto rotate said spindle in one direction when said element is at one limit of its shift, and

to reversely rotate said spindle when said element is atthe other limit of its shift; and a transmission connecting said spindle and said'element for enabling said spindle to be manually translated when said element is rotated under manual actu- 18. A tapping machine combining a rotatable and translatable spindle; a normally stopped motor for rotating the spindle selectively in reverse direction; a set of forward and reverse switches for said motor; a manually operated member having a connection with said switches for actuating said switches; a rack and pinion mechanism for translating said spindle; and a motion transmitting element between said rack and pinion mechanism and said manually operated member whereby said spindle may be started, stopped, or reversed and translated in either direction by said manually operated member.

19. In a drilling and tapping mechanism, the combination of a reversible motor for rotating a tool'spindle in reverse directions, a reversing switch therefor, an additional reversing switch therefor, means for translating the tool spindle in reverse directions including a rotatable element comprising a pair of members rotatable together and also having angular movement between them, a member actuated by such angular movement and having operative connection with said additional reversing switch for operating the same, and means to lock said members together to neutralize said additional reversing switch and to make said first-named switch solely efiective for reversals of said motor.

20. The combination of a tool spindle, a reversible electric motor for rotating the same in reverse directions, switches respectively for forward and reverse rotations of said motor for forward and reverse rotations of said tool spindle, operating means for selectively operating said switches for forward and reverse rotations of said motor and said tool spindle and for neutralizing both said switches, means for operatively translating said tool spindle comprising parts having relative movement between them and constructed for combined movements, an additional switch for opposite rotations of said electric motor and said tool spindle for tapping operations, a part having operative connection with one of said parts for reversing said last-named switch, and means for locking said parts together for neutralizing reversal in said additional switch.

21. The combination of a tool spindle, means for rotating the same in reverse directions comprising a control member, translating means for translating said spindle in reverse directions comprising members having spaced connection between them, and means for reversing rotation of said spindle comprising an element having rotative connection with one of said members and cam connection with the other of said members whereby to move said element for actuation of said control member to reverse rotation of said tool spindle.

22. The combination of a tool spindle, means for rotating the same in reverse directions, translating means for translating said tool spindle in reverse directions comprisingmembers having oppositely spaced connections between them upon reversals thereof, means for reversing rotation of said spindle having operative connection with one of said members to be actuated thereby during spatial movements between said members, and means neutralizing said spatial movements.

23. The combination of a tool spindle, means for rotating the same in reverse directions, translating means for translating said tool spindle in reverse directions comprising members having oppositely spaced connections between them upon reversals thereof, means for reversing rotation of said spindle having operative connection with one of said members to be actuated thereby during spatial movement between said members, additional means for reverse rotation of said spindle, and means neutralizing said spatial movements and rendering said additional means eflective for reverse rotations of said spindle.

24. In means for changing the direction of rotation of a tool spindle, a control part for 25. In means for changing the direction of rotation of a tool spindle, a control part for effecting such change, means for changing the direction of translation of the tool spindle comprising a pair of parts having idle angular movement between them, a shiftable part having rotative connection with one of said parts and endwise movement with the other of said parts for moving said control part to effect such change, and means to lock said parts together for neutralizing said control.

26. The combination of a tool spindle, means for translating said'tool spindle in opposite directions comprising a multi-part rotatable element the parts whereof have relative move ment between them, means for rotating said tool spindle in opposite directions including a direction control member, an axially movable sleeve about the axis of said rotatable element rotatable with one of said parts thereof and relatively to the other of said parts thereof and having operative connection with said direction control member, and means between said other of said parts and said sleeve for moving said sleeve axially during said relative movement for actuation of said direction control member.

27. The combination of a tool spindle, means for translating said tool spindle in opposite directions comprising a multi-part rotatable element the parts whereof have relative movement between them, means for rotating said tool spindle in opposite directions including a direction control member, an axially' movable sleeve about the axis of said rotatable element rotatable with one of said parts thereof and relatively to the other of said parts thereof and having operative connection with said direction control member, means between said other of said parts and said sleeve for moving said sleeve axially during said relative movement for actuation of said direction control member, and means for locking together said parts having relative movement between them and said sleeve for neutralizing said axial movement of said sleeve and rotate with both said parts between angular effecting such change, means for changing the.

direction of translation of the tool spindle comprising a pair of parts having idle angular movement between them, and a shiftable part having rotative connection with one or said parts and endwise movement with the other of said parts for moving said control part to eflect such change.

movements, and said sleeve having such connection with the other of said parts so as to be moved endwise during such limited angular movement and having such operative connection with said reversing control part as to reverse rotation of said spindle.

29. In means for changing the direction of rotation of a tool spindle, a control part for eflecting such change, means for changing the direction of translation of the tool spindle comprising a pair of parts having idle angular movement between them, and a shiftable part having rotative connection with one of said parts and endwise movement relative to the other of said parts for moving said control part to effect such change.

LAWRENCE LEE SCHAUER. 

